INDUCED MAGNETIC-ANISOTROPY IN FE80B20 METALLIC-GLASS BY MECHANICAL MILLING

By means of transmission Mossbauer spectroscopy, the effect of mechani cal milling on the magnetic anisotropy of Fe80B20 metallic glass has b een studied. On the basis of variation of the areal ratio R(21) of the second to the first Mossbauer line with milling time, it was found th at a rotation of the average magnetic-moment directions from the in-pl ane to an out-of-plane orientation may take place by mechanical millin g without onset of bulk crystallization, and that the distribution of the magnetic-moment directions becomes random after the bulk crystalli zation has occurred. The induced out-of-plane magnetic anisotropy by m echanical milling can be attributed to the occurrence of the chemical short-range order and surface crystallization in the Fe80B20 metallic glass. The latter effect may cause the formation of compressive stress es in the bulk and therefore a rotation of magnetic-moment directions in the Fe80B20 metallic glass. (C) 1996 American Institute of Physics.